Brake for printing-presses.



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PPLIUTIH :FILED JAN. 6,'1910.

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BRAKE FOR PRINTING PRESSES. APPLIUATIDNHLBI) JAN. 6,1910.

Patented Feb. 28, 191'1.

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.- ATTORNEYS UNITED STATES PATENT OFFICE.

JOHN THOMSON, OF NEW YORK, N. Y., ASSIGNOR TO JOHN THOMSON EESS COMPANY,

OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JE SEY.

BRAKE FOR PRINTINGePRESSES.

To all whom 'it may concern:

Be it known that I, Jol-1N THOMSON, a citizen of the United States, and aresident of the borough of Manhattan of the city of New York, in the county and State of New York, have invented certain new and useful Improvements in Brakes for` Printing-Presses, of which the following is a specification, reference being had to the ac companying drawings, forming a part hereof.

The invention relates more particularly to improvements in ily-wheel brake mechanisms for printing presses, and the main object thereof is to provide a self contained structure which shall be exceedingly rigid and enduring and one in which the brakeshce shall be adapted to have a wedge-like action (which has been found effective in the case of an earlier construction of applicant in bringing liyvvheels making from two hundred to three hundred revolutions a minute to a dead stop), without imposing a severe wrenching strain upon the coperating or adjacent parts.

In the present improved construction, the brake-shoe is mounted at one side of the fly-wheel shaft, that is to one side of a vertical line through the center of said shaft, and a lever independent of the brake-shoe is provided for driving it upwardly so that the face of the brake-shoe may impinge obliquely upon the face of the fly-wheel. Heretofore, it has been difficultto obtain the high elfectiveness of the brake and at the same time to enduringly mount it so that the severe wrenching strains caused by the wedge-like action. would not bring unr due strain upon the adjacent parts. As was generally the case, the shoe was carried upon the toeor bell crank extension of the brake lever, a construction which obviously is not well adapted to bear the strain placed upon it under the usual operating conditions. In the present case, to overcome the objections of the earlier designs, the shoe has been mounted freely upon a vertical pin which is firmly united to the frame of the machine and which readily transmits the strains imparted thereto to the frame.

The invention will now be described with' reference to the accompanying drawings in which,

Figure 1 1s a view in elevation of a portion of a press to which the improvements Serial No. 536,764.

have been applied, looking in the direction of the plane of the fly-wheel. Fig. 2 is a similar view, partly in section, and at right angles to the plane of Fig. 1, the section being indicated by the irregular' broken line 2 2 in Fig. l, and, Fig. 3 is a view in elevation of the hand lever detached from the press and as viewed from the inside.

The flywheel a may be mounted in the usual manner upon the fly-wheel shaft h which is journaled in the frame c of the press. The hand lever cl for operating the brake is pivoted at e to a bracket f which is bolted to the frame and which rests Clown upon the heavy bottom flange g of the press. This bracket is located to one side of the vertical line through the center of the iiywheel'shaft and is provided with a vertical steel pin 7L which is securely inserted in the bracket, as indicated in Fig. l, preferably at the point where the bracket rests down upon the bottom flange. Upon this steel pin 7a the brake-sheet' is freely mounted so as to be capable of sliding up and down thereon.

The underside of the brake-shoe is provided with two l'lat portions 7c and these fiat portions are engaged respectively by pronged bell-crank extensions Z of the hand lever d which extensions embrace the pin h and the portion of the brakeshoe between the flat portions k thereof (Fig. 2). The ends of the extensions Z arevsomewhat rounded in order to bear suitably against the brakeshoe.

4Now, by swinging the lever into the position shown in full lines in Fig. 1, the brake-v shoe will be raised to the position shown in Fig. 2 of the drawing, where the face of the vshoe is brought into oblique contact with the face of the flywheel. On the other hand, when the lever is thrown into the posi* tion indicated in broken lines in Fig. l, the brake-shoe will slide down by gravity upon its bearing pin, leaving the flywheel free. It will be seen, therefore, that the bellcrank forks of the hand lever actonly to impart motion and pressure to the shoe, the reacting thrust being resisted by the bearing in the shoe and its pin in the bracket.

It will be understood that various changes may be made in the construction shown and described without departing from the spirit of the invention. It will also be understood that when the press is driven by a belt operating on pulleys, Which latter may be mounted as usual on an outward extension of the fly-'Wheel shaft, a suitable fork for shifting the belt may readily be applied to the hand lever, as usual; or, if

the actuation of the press is by an elect-ric` motor, then the circuit controlling switch may 'with equal facility be 'connected 'to op erate oonjunctively with the action of the the frame and to Whichhthe lever is pivoted, a vertical pin upon said bracket, and a brake-shoe freely mounted upon said pin to ni'ove vertically, the forked end of the lever embracing the pin and engaging the underside of the brake-shoe to raise it into an oblique Wedg'ing contact with the flywheel and permitting it to drop again by gravity When the laand lever is released.

This specification signed and witnessed this 29th day of December, A. D., 1909.

JOHN THOMSON. Sign-ed in the presence Voi- E. E. Karolien, H. C. Cross.

Copies of this patent may b'e obtained for five cents eac-h, by addressing the Commissioner of latents, Washington, ED. C. 

